Exemplary embodiments of the present invention relate to a radiation emitter for directional energy with a device for coupling in radiation from at least one radiation generator and one radiation combining device, which combines the radiation into bundled radiation.
European patent document EP 2182596 A1, assigned to the same assignee as the present application, discloses a radiation emitter for directional energy, which can also be called a tactical radiation emitter or an energy weapon and, for example, can be embodied as a laser weapon.
This known radiation emitter comprises a device for coupling in radiation from at least one radiation generator and one radiation combining device, in order to combine the radiation to a high-energy combined beam. The radiation generator may represent an industrially available laser, with the use of generic laser weapons being seen in the defense against missiles, where here, via a bundled laser beam, thermal impact is applied upon the exterior skin of a missile at long distances of up to several hundred kilometers, allowing the destruction of the missile. An example is here the airborne laser weapon system Boeing YAL-1 of the U.S. Air force.
Another application of such a high energy radiation weapon is in the battlefield at a distance from a few hundred meters to several kilometers. Here, by using the high-energy beam, thermal effects can be applied upon weapons or ammunition rendering them ineffective.
In any case it is required, however, to provide a radiation emitter for directional energy capable of emitting very high radiation and precisely directing it to the target such that the radiation, upon impact on the target object, is still sufficiently high to cause the desired thermal effect.
Successful defense against grenade launchers and similar targets using a high-energy laser weapon requires the generation of a focal point on the target with its intensity exceeding 10 kW/cm2 at a distance from approximately one to approximately three kilometers. In order to fulfill these requirements, the laser weapon needs a laser source with a capacity exceeding 100 kW.
The development of high-energy radiation emitters, for example high energy lasers suitable for such applications, is time-consuming and costly and bears considerable risks for realization.
Lasers are already available for industrial applications, for example laser welding, showing a power of several kilowatts and an almost diffraction limited beam quality (diffraction parameter M2<1.1). This power, which probably can be slightly increased, is far from sufficient to fulfill the requirements of a tactical radiation emitter as explained above, which can apply an effective energy upon an object from over several hundred meters or even several kilometers away.
Exemplary embodiments of the present invention provide a radiation emitter for directional energy, which for manageable costs, allows effective energy to be applied upon a mobile object from a distance of several hundred meters to several kilometers.
Exemplary embodiment of the present invention further provide a radiation emitter for directional energy with a device for coupling in radiation from at least one radiation generator and one radiation combining device, which combines the radiation to bundled radiation, with the radiation combining device comprising a telescopic optic with a collimation reflector and a secondary mirror and the device being embodied for receiving directional radiation from a plurality of light conductors from at least one radiation generator.
The device for receiving directional radiation allows the coupling of high-energy radiation from one or a plurality of preferably commercially available radiation emitters, for example industrially available lasers, which are intended for processing parts and are available at low costs in large numbers. The beams radiation emitted by these radiation emitters is transferred via light conducting devices to a receiving optic of the radiation emitter according to the invention and coupled there. The collimation reflector serves, among other things, for directing the radiation bundled in this fashion to a target object. Additional functions of the collimation reflector are explained in the following and the secondary mirror serves, among other things, for the focusing of the combined beam onto a target object.
The radiation emitter is preferably provided for a spatially largely coaxial coupling in of radiation from at least one high-energy laser light source. For this purpose, optic coupling devices may be provided at the telescopic optic, via which the radiation emitted by one, preferably at least two generators in the form of high-energy directional beams can be coupled in from the end sections of fiber optic conductors. Here, for example, industrial solid state lasers with a wavelength of 1.07 μm can be used as the generators of the high-energy laser beams. This arrangement allows a cost-effective application of commercially available radiation generators and energy to be coupled in the radiation emitter according to the specific energy required respectively for each application by coupling in energy from a plurality of radiation generators.
The radiation emitter according to the invention is preferably embodied to bundle radiation into a parallel beam via a parabolic mirror and for conducting radiation in individual beam axes via a beam splitter to different sub-apertures of the telescopic optic.
In order to combine radiation from several laser beams or radiation energy, the laser radiation emitted from the ends of the above-mentioned fiber optic conductors is bundled via the parabolic reflector into a parallel beam with a small diameter, typically a diameter from one to two centimeters, and directed in the individual beam axes via the beam splitter and particularly additional optic components to different sub-apertures of the telescopic optic.
The beam splitter preferably is a deflector that articulates in two axes, which deflects light in the beam path to Piezo tilting deflectors, preferably rapid-controlled ones tilting about two axes. For this purpose, the radiation emitter preferably comprises, in addition to the beam splitter, at least one deflector that articulates in two axes and a beveled mirror, with the deflector being embodied to deflect radiation in the direction towards the beveled mirror and the beveled mirror being embodied to deflect radiation in the direction towards the secondary mirror.
According to the invention, the secondary mirror is embodied in a displaceable fashion with respect to the collimation deflector along a longitudinal axis of the telescopic optic. The different sub-apertures of the telescopic optic ensure that the radiation is focused coaxially on the target object. The common focusing ultimately occurs by an axial displacement of the secondary mirror with respect to the collimation deflector along a longitudinal axis of the telescopic optic.
In order to align the radiation emitter with its telescopic optic on the target object, it is preferably provided for the radiation emitter to comprise at least a camera and a control device for analyzing image data recorded by the camera and a device for aligning the radiation emitter using a control device and the analyzed image data.
The alignment of the radiation emitter occurs, therefore, based on a camera following the target object and an allocated track electronic. In this way, preferably a first or coarsely adjusted alignment to the target object is yielded detecting the target object.
The invention further provides a laser device illuminating the target object for a fine adjustment of the radiation and/or the radiation emitter to the target object, which emits light with a wavelength different from the wavelength of the radiation of at least one radiation emitter, and the collimation reflector and a beveled mirror are embodied for deflecting laser light reflected by the target object in the direction of the radiation paths of the radiation generator.
Using the illuminating laser, the target object can be irradiated over a relatively large area, the light emitted by the illuminating laser has a wavelength that is different from the wavelength of the radiation emitted by the radiation generator. The light of the illuminating laser reflected by the target object is bundled via the collimation reflector and distributed via the beveled mirror and the reflector, which can tilt about two axes, into the radiation paths of the individual radiation emitters of the radiation generation device.
For a precise alignment of the radiation and/or the radiation emitter to the target object, the radiation emitter preferably comprises at least one position-sensitive detector and/or a camera for recording laser light reflected by the target object and a control device for detecting relative angular misalignments in the radiation paths based on data of the detector and/or the camera and their correction via the reflector and/or the secondary mirror.
The light of the illumination laser reflected into the radiation paths of the radiation emitter is displayed by the above-mentioned beam splitter on the position-sensitive detector and/or a camera. Here, the collimation reflector serves as a receiving optic and ensures, due to its large aperture, high optic resolution and light intensity. This is advantageous, for example, when a camera is used for detecting positions and precise alignment, which may be provided according to the invention.
The detector and/or the camera provide data signals, based on which, via a precise tracking electronic, relative angular misalignments are determined in the individual radiation paths of the high-energy beams, and are corrected by the above-mentioned control device addressing the reflector that can tilt and the secondary mirror, also embodied as a tilting mirror. This control also allows a correction of the angular misalignments generated by atmospheric turbulence effects on the path traveled by the energy radiation to the target object.
According to the invention, at least one laser light source is provided, which emits a laser light beam coupled into the radiation path of the radiation generator, with its progression being detected by the detector and/or the camera for adjusting radiation paths of the radiation generator. For this purpose, in accordance with the present invention the light emitted by the laser light source is different with regards to its wavelength from the wavelength of the radiation of the radiation generator and otherwise follows the radiation path of the radiation of the radiation generator. This way, the laser light used for adjusting and harmonizing individual radiation paths passes the optic path of the effective radiation.
Finally, according to the invention the radiation emitter comprises means for emitting a light beam, directed via a wavelength-sensitive beam splitter to a position-sensitive detector and/or a camera, which can be detected for analyzing an angular misalignment. This light beam can be displayed, similar to the reflected radiation of the illumination laser, via the wavelength-sensitive beam splitter on the position-sensitive detector and/or the camera, and angular misalignments can be calculated therefrom and corrected via tilting reflectors.